As a method of forming a resist pattern on a semiconductor wafer or a glass substrate for a liquid crystal display panel, a method using a chemically amplified photosensitizing resist is known. When the resist is exposed by an exposure machine with the use of a pattern mask (pattern exposure), acid is generated in the exposed part. When the exposed part is further heated, the acid awakes to become soluble in alkali. By supplying the part soluble in alkali with a developer, a circuit pattern is formed.
Since a circuit pattern becomes finer and finer, a circuit pattern is required to have a high resolution. For example, an extreme ultraviolet (EVU) exposure is known as means for coping with this request. However, when a light intensity of an exposure light source for the EUV exposure is increased, an apparatus therefor becomes large, which results in increased cost. On the other hand, an apparatus of a small size is poor in light intensity, which reduces a throughput.
In addition, JP2015-156472A discloses an exposure apparatus using LEDs. In this exposure apparatus, a wafer coated with a chemically amplified photosensitizing resist is pattern-exposed with the use of a pattern mask, and then the pattern-exposed area is subjected to a flood exposure so as to improve an in-plane uniformity of a line width of the pattern on the wafer. The exposure apparatus is configured to move a wafer in a housing from one side to the other side thereof. The LEDs emit light to cover a wafer movement area in a width direction. While the LEDs emit light, a wafer is moved from one side to the other side to pass transversely across an irradiation area, so that the whole surface of the wafer is irradiated with light.
When a coating film is formed on a substrate, the substrate is pattern-exposed by using a pattern mask and then the substrate is subjected to a developing process, there is used a substrate processing system formed by connecting a coating and developing apparatus that performs formation of a coating film and a developing process, and an exposure apparatus that performs a pattern exposure process. In this case, the exposure apparatus that further exposes a pattern exposed area after a pattern exposure process is incorporated in the coating and developing apparatus. In this case, with a view to avoiding enlargement of the apparatus, a flood exposure apparatus is preferably provided with a common loading and unloading port through which a wafer is loaded and unloaded so as to avoid enlargement of a wafer transport area in a substrate processing apparatus.
In the case of such an exposure apparatus, in order that a wafer is loaded into the exposure apparatus, and that the wafer is unloaded therefrom after the whole surface of the wafer has been subjected to an exposure process, the wafer passes through a light irradiation area twice. Namely, upon loading, the wafer is moved from the loading and unloading port side to an inside, and upon unloading the wafer is moved from the inside to the loading and unloading port side. When a wafer passes through the light irradiation area plural times, it is difficult to adjust an amount of irradiation. Thus, it is necessary for a wafer to be moved below a light source without the intention of being exposed. However, if LEDs are turned off so as not to expose a wafer, it takes a long time for a light intensity of LEDs to become stable after the LEDs are again turned on. Thus, a throughput of the apparatus lowers.